Partial Right Atrial Anchoring of a Mitral Valve Prosthesis as a Bail-out Strategy in a Re-redo Situation with a Mitral Annulus Destroyed by Endocarditis

Background: Implantation of a prosthetic valve in a severely damaged mitral annulus destroyed represents a challenge. This applies in particular, where the juxta-annular atrial tissue is fragile, too, or where the left atrium is too small for intra-atrial implantation.

Case Presentation: A 56 year-old patient presented with endocarditis 6 years after mitral valve replacement. One year earlier, when she had undergone redo surgery for posterior detachment of the prosthesis, exposure of the mitral valve was nearly impossible due to an unfavorable anatomy with a tilted position of the prosthesis and a particularly small left atrium. When she was referred to our department, she was in cardiogenic shock and had undergone cardiopulmonary resuscitation. There was severe mitral regurgitation caused by anterior detachment of the valve. In spite of a EuroSCORE of 87 and considerable comorbidity including liver cirrhosis (Child A), the patient was scheduled for emergent re-redo surgery. Inspection of the mitral valve, exposed via a modified Dubost transseptal approach, showed the prosthesis largely destroyed with the sewing ring detached from its seat in the mitral annulus over the entire length of the anterior leaflet. The mitral annulus was fragile with multiple deep endocarditic lesions and abscesses and required extensive debridement. After removal of all infected and necrotic tissue, the annulus was too damaged and friable to provide secure seating for a new prosthesis. Therefore, 6 of the sutures for a new Hancock 27 mm mitral valve were anchored within the annulus with deep stitches from the right atrium through the septum into the left atrium. The other sutures were placed in usual fashion. Closure of the septum and atrium, weaning from CPB and the remaining parts of the procedure were also implemented as usual. After an ICU stay of 10 days, the patient was transferred back to the referring hospital where she took an uncomplicated further course. Four months after the procedure, we encountered her in good functional condition with a satisfactory quality of life and no signs of recurrence.

Conclusion: When implantation within the mitral annulus is impossible and intra-atrial implantation is rendered unfeasible by pathology of the left atrial tissue or an unfavorable anatomy, implantation of a mitral valve prosthesis with part of the stitches placed from the right atrium through the septum is a safe bail-out strategy.